Hollow carbon architectures with mesoporous shells via self-sacrificial templating strategy using metal-organic frameworks

The rational design and fabrication of ordered mesoporous materials with highly exposed surface area are of great significance to address the fundamental challenges in electrochemistry-related applications by providing more active sites and fast ion/gas diffusion channel. In this work, a self-template method is reported to prepare hollow-structured mesoporous carbon (HOMC) nanoplates by depositing resol-F127 micelles onto the surface of metal-organic-framework (MOF) nanoplates, followed by hydrothermal reaction and carbonization. The parameters influencing the morphology and microstructure of the HOMC materials, i.e., the MOF-to-resol-F127 ratio and the concentration of resol-F127 micelles, are systematically investigated. Fe-doped HOMC (Fe/ HOMC) is obtained after carbonization, as a result from adding FeCl3 during the hydrothermal reaction. Benefiting from morphological aspects, such as the nanoplate shape, the hollow structure, and mesoporous walls, the Fe/HOMC exhibits higher electrocatalytic activity and efficiency than the commercial Pt/C during oxygen reduction reaction (ORR). In addition, when compared to traditional Pt/C benchmark, the Fe/HOMC shows a superior durability and tolerance to methanol poisoning while operating for ORR. The assembled Zn-air battery possesses high power densities with excellent cycling stability. The strategy proposed here can provide a new avenue for the design of ordered mesoporous materials with hollow structure for a wide variety of applications.

Automated summary

In this study, hollow-structured mesoporous carbon (HOMC) nanoplates were successfully synthesized using a self-template method, with Fe-doped HOMC (Fe/HOMC) exhibiting higher electrocatalytic activity, efficiency, durability, and tolerance to methanol poisoning compared to traditional Pt/C benchmark. The Fe/HOMC also showed promising application in Zn-air batteries with high power densities and excellent cycling stability, demonstrating a new avenue for the design of ordered mesoporous materials with hollow structure.